1. Field of the Invention
The invention relates to a circuit for supplying power to a ventilation fan for cooling the interior of a motor vehicle and/or to a motor vehicle battery by means of solar cells, With a manually actuated switch for switching the solar cell power supply to the ventilation fan or battery.
2. Description of Related Art
A circuit of this type is known from German Patent 36 10 767 C2. The solar cell units are series connected in the position of the manually activated switch for supplying of solar cell current to the battery, while in the switch position for supplying solar cell current to the ventilation fan, the solar cells are connected in parallel in order to deliver, in the former case, a voltage above the battery voltage (conventionally 12 V), and in the latter case, to deliver a voltage below the battery voltage (conventionally roughly 6 V). Preferably, the manually activated switch is replaced by the ignition lock to vent and cool the motor vehicle interior with the vehicle stopped and with solar irradiation of the solar cells, while when driving the battery is charged.
German Patent DE 29 52 080 C2 discloses a circuit for solar cell power supply for a ventilation fan for cooling the interior of a motor vehicle which can be set selectively to summer or winter operation. During summer operation, the ventilation fan is started only beginning at a predetermined interior temperature.
German Patent DE 41 39 435 C2 discloses charging of the battery depending on its charging voltage and the no-load voltage of the solar cell in solar cell power supply of a motor vehicle battery.
Furthermore, different designs switches are known, including switches with rockers and switches with symbols which are assigned to their actuating element and which can be located directly on the actuating element, if necessary. Furthermore, light emitting diodes located in the actuating element of the switches are known for optical indication of the switch state. In this connection, for example, published German Patent Application DE 42 29 756 A1 discloses marking of the blocking position of a manual actuation element by means of an imprinted color or imprinted character symbol. A switch with the actuating element in the form of a rocker with button function in the neutral position and illuminated marking of all three switch positions is known from published German Patent Application DE 42 42 100 A1.